The present invention relates to a combination of an herbal extract and an essential oil which shows unexpected synergistic anti-microbial activity and, more particularly, to such a combination which can exert anti-microbial activity in the oral cavity and on mucosal organs.
Recently, interest has been displayed in the medicinal properties of herbal preparations. Herbal preparations are considered "more natural" and are therefore viewed as less toxic by the consumer. These preparations are being sold for a number of indications, including anti-bacterial activity.
For example, a combination of Echinacea (Echinaceae angustifoliae radix) and Plantago (Plantago major) is available from Dolisos Laboratoires, Israel, as "Plantspray". Plantspray is intended as a composition for oral hygiene. According to the product literature, Plantspray has anti-bacterial activity in the oral cavity and can therefore promote the general health of oral tissues, as well as cosmetic concerns such as malodorous breath. Another herbal combination, Echinacea and Propolis, is also available from Dolisos Laboratoires as "Echinacea Propolis Tabs". Propolis wax is the resinous substance found in beehives. The echinacea and propolis wax combination is also intended for oral hygiene.
However, although combinations of herbal extracts have enjoyed commercial success, relatively few of these combinations have demonstrated proven synergistic anti-microbial activity.
Synergistic combinations of non-herbal, anti-bacterial compositions are well known in the prior art. In certain of these combinations, one ingredient has high anti-bacterial activity alone, while the other ingredient has little or no anti-bacterial activity. In combination, however, these two ingredients have far higher anti-bacterial activity than could be expected from their individual activities, thus displaying synergism. One example of such a combination is amoxicillin and clavulanate. Alone, clavulanate has little anti-bacterial activity, but in combination with amoxicillin, it shows highly synergistic activity [Goodman and Gilman's The Pharmacological Basis of Therapeutics, A. G. Gilman et al., eds., Pergamon Press, Inc., 1990, p. 1093].
The advantage of such synergism is that the effectiveness of the anti-bacterial composition is greatly increased, without a concomitant increase in the dosage level or rate of administration. Lower quantities of each substance could potentially be administered in combination yet still achieve the desired therapeutic effect. Such synergistic combinations could prove particularly important in the treatment of delicate or sensitive tissues, such as the oral mucosa, where the ability to reduce the concentration of individual ingredients could prove important. Unfortunately, as noted above, although many combinations of herbal preparations are touted as having "anti-microbial activity", few have proven synergistic, rather than merely additive, activity.
There is thus a widely recognized need for, and it would be highly advantageous to have, a herbal preparation with proven synergistic anti-microbial activity, particularly for oral hygiene.